A robot and a method for compensating for longitudinal misalignment thereof

Abstract

The application provides a robot and a method for compensating longitudinal deviation of the robot. The robot comprises a cantilever part, a first end of which is connected to a base and a second end of which is suspended, wherein a thermal stress compensation mechanism and a temperature adjusting mechanism are arranged on the body of the cantilever part, the thermal stress compensation mechanism has a different thermal expansion coefficient from the body of the cantilever part, and is used for providing an upward force to the body of the cantilever part within a target temperature range, and the temperature adjusting mechanism is used for adjusting the temperature of the thermal stress compensation mechanism to the target temperature range. The robot can improve the drooping phenomenon of the cantilever end of the robot caused by its own gravity, thereby improving the motion accuracy of the robot during long-distance transmission, ensuring the stability of long-time transmission of workpieces, and helping to expand the application boundary of the robot in the high-precision manufacturing scene.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing technology, and specifically to a robotic arm, a method for compensating for longitudinal offset of the robotic arm, and a computer-readable storage medium. Background Technology

[0002] Vacuum robots, as key transfer devices in semiconductor manufacturing, materials synthesis, and other fields, often need to perform long-distance gripping and transfer of workpieces in high-temperature chamber environments. Existing vacuum robots face the following technical bottlenecks in this application scenario.

[0003] First, when a mechanical cantilever extends a long distance, its own weight and the changes in material mechanical properties under high temperatures can cause the sag at the cantilever end to exceed the allowable range. Second, during long-distance movement of the mechanical cantilever, the combined effect of transmission errors and structural deformation caused by high temperatures can easily lead to distortion of motion accuracy and affect the stability of workpiece transmission. Furthermore, there is currently no mature compensation algorithm to correct displacement deviations in the Z-axis direction of the mechanical cantilever caused by temperature drift and load changes, thus limiting the application of robotic arms in high-precision manufacturing scenarios.

[0004] To address the aforementioned problems in the prior art, there is an urgent need in the field for an improved robotic arm technology that can mitigate the drooping phenomenon of the robotic arm cantilever due to its own gravity, thereby improving the motion accuracy of the robotic arm during long-distance transmission, ensuring the stability of workpiece transmission over long periods, and helping to expand the application boundaries of robotic arms in high-precision manufacturing scenarios. Summary of the Invention

[0005] The following provides a brief overview of one or more aspects to offer a basic understanding of them. This overview is not an exhaustive summary of all conceived aspects, nor is it intended to identify key or decisive elements of all aspects, nor to define the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed descriptions that follow.

[0006] To overcome the aforementioned deficiencies in prior art, this invention provides a robotic arm, a method for compensating for longitudinal offset of the robotic arm, and a computer-readable storage medium. These methods can improve the sagging phenomenon caused by the weight of the robotic arm's cantilever end, thereby improving the motion accuracy of the robotic arm during long-distance transmission, ensuring the stability of workpiece transmission over long periods, and helping to expand the application boundaries of robotic arms in high-precision manufacturing scenarios.

[0007] Specifically, the robotic arm provided according to the first aspect of the present invention includes: a cantilever portion, a first end of which is connected to a base and a second end of which is suspended, wherein the body of the cantilever portion is provided with a thermal stress compensation mechanism and a temperature adjustment mechanism, the thermal stress compensation mechanism having a different coefficient of thermal expansion from the body of the cantilever portion, for providing an upward force to the body of the cantilever portion within a target temperature range, and the temperature adjustment mechanism for adjusting the temperature of the thermal stress compensation mechanism to the target temperature range.

[0008] Furthermore, the above-mentioned method for compensating for longitudinal offset of a robotic arm provided by the second aspect of the present invention includes: adjusting the temperature of the thermal stress compensation mechanism of the robotic arm to a preset target temperature range via the temperature adjustment mechanism of the robotic arm provided by the first aspect of the present invention, so as to provide an upward force to the cantilever portion of the robotic arm via the thermal stress compensation mechanism.

[0009] Furthermore, according to a third aspect of the present invention, a computer-readable storage medium is provided having computer instructions stored thereon. When the computer instructions are executed by a processor, the above-described method for compensating for longitudinal displacement of a robotic arm provided in the second aspect of the present invention is implemented. Attached Figure Description

[0010] The above-described features and advantages of the present invention will be better understood after reading the following detailed description of embodiments of the present disclosure in conjunction with the accompanying drawings. In the drawings, components are not necessarily drawn to scale, and components having similar related characteristics or features may have the same or similar reference numerals.

[0011] Figure 1 A schematic diagram of a robotic arm provided according to some embodiments of the present invention is shown.

[0012] Figure 2A A schematic diagram of the cantilever section provided according to some embodiments of the present invention is shown.

[0013] Figure 2B for Figure 2A The diagram shows the structure of the cantilever after T-axis rotation.

[0014] Figure 3 A bottom view schematic diagram of the third arm provided according to some embodiments of the present invention is shown.

[0015] Figure 4 A flowchart is shown of a method for compensating for longitudinal offset of a robotic arm according to some embodiments of the present invention.

[0016] Figure 5 A flowchart is shown of a method for compensating for longitudinal offset of a robotic arm according to other embodiments of the present invention.

[0017] Figure label: 100 robotic arms; 110. Cantilever section; 120 base; 121 Root direct-drive servo motors; 130 Thermal stress compensation mechanism; 141 First arm segment; 142 Second arm; 143 Third arm; 151 First joint; 152 Second joint; 160 (finger); 310 Reinforcing rib; S410 Step; Steps S510~S520 Detailed Implementation

[0018] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Although the description of the present invention is presented in conjunction with preferred embodiments, this does not mean that the features of the invention are limited to these embodiments. On the contrary, the purpose of describing the invention in conjunction with embodiments is to cover other options or modifications that may be derived based on the claims of the present invention. To provide a thorough understanding of the invention, many specific details will be included in the following description. The invention may also be implemented without using these details. Furthermore, to avoid confusion or obscuring the focus of the invention, some specific details will be omitted in the description.

[0019] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0020] Furthermore, the terms "upper," "lower," "left," "right," "top," "bottom," "horizontal," and "vertical" used in the following description should be understood as the orientations shown in the relevant paragraphs and accompanying drawings. These relative terms are for illustrative purposes only and do not imply that the described apparatus must be manufactured or operated in a specific orientation, and therefore should not be construed as limiting the invention.

[0021] It is understood that although terms such as "first," "second," and "third" may be used herein to describe various components, regions, layers, and / or parts, these components, regions, layers, and / or parts should not be limited by these terms, and these terms are only used to distinguish different components, regions, layers, and / or parts. Therefore, the first components, regions, layers, and / or parts discussed below may be referred to as second components, regions, layers, and / or parts without departing from some embodiments of the present invention.

[0022] As mentioned above, existing vacuum manipulators face the following technical bottlenecks in this application scenario. First, when the mechanical arm extends a long distance, the sag at the cantilever end exceeds the allowable range due to its own weight and the changes in material mechanical properties under high temperature conditions. Second, during the long-distance movement of the mechanical arm, the superposition of transmission errors and structural deformation caused by high temperature can easily lead to distortion of motion accuracy and affect the stability of workpiece transmission. In addition, there is currently no mature compensation algorithm to correct the displacement deviation in the Z-axis direction of the mechanical arm caused by temperature drift and load changes, thus restricting the application of manipulator equipment in high-precision manufacturing scenarios.

[0023] To address the aforementioned problems in the prior art, this invention provides a robotic arm, a method for compensating for longitudinal offset of the robotic arm, and a computer-readable storage medium. These methods can improve the sagging phenomenon caused by the weight of the robotic arm's cantilever end, thereby enhancing the motion accuracy of the robotic arm during long-distance transmission, ensuring the stability of workpiece transmission over extended periods, and helping to expand the application boundaries of robotic arms in high-precision manufacturing scenarios.

[0024] In some non-limiting embodiments, the robotic arm provided in the first aspect of the present invention can be used to perform the longitudinal offset compensation method of the robotic arm provided in the second aspect of the present invention, thereby compensating for its own longitudinal offset during the process of extending and transporting the workpiece.

[0025] Specifically, in some non-limiting embodiments, the computer-readable storage medium described above in the third aspect of the present invention stores a computer program product thereon. The computer program product includes computer instructions. A processor is connected to the memory and configured to execute the computer instructions included in the computer program product to implement the longitudinal offset compensation method for the robotic arm provided in the second aspect of the present invention.

[0026] The working principle of the aforementioned robotic arm will be described below with reference to embodiments of methods for compensating longitudinal offset of the robotic arm. Those skilled in the art will understand that these embodiments of methods for compensating longitudinal offset of the robotic arm are merely non-limiting implementations provided by this invention, intended to clearly demonstrate the main concepts of the invention and provide specific solutions convenient for public implementation, rather than limiting all working methods or functions of the robotic arm. Similarly, this robotic arm is only one non-limiting implementation provided by this invention and does not limit the implementing entities and execution steps of each step in these methods for compensating longitudinal offset of the robotic arm.

[0027] First, please refer to Figure 1 . Figure 1 A schematic diagram of a robotic arm provided according to some embodiments of the present invention is shown.

[0028] like Figure 1 As shown, in some embodiments of the invention, the robotic arm 100 may mainly include a cantilever portion 110 and a finger portion 160 for carrying wafers.

[0029] Specifically, it can be combined with Figure 2A A shared understanding. Figure 2A A schematic diagram of the cantilever section provided according to some embodiments of the present invention is shown.

[0030] exist Figure 1 and Figure 2A In the illustrated embodiment, the first end of the cantilever 110 is connected to the base 120, while its second end is suspended. Therefore, the cantilever 110 has the structural characteristics of being fixed at the root and suspended at the end. When the cantilever 110 is extended over a long distance, its second end, which is away from the fuselage, will sag due to its own weight, which may easily lead to positioning deviation of the second end (i.e., the end point) of the cantilever 110.

[0031] In this regard, such as Figure 1 As shown, in the embodiment provided by the present invention, the cantilever 110 may be provided with a thermal stress compensation mechanism 130 (e.g., Figure 1 The thermal stress compensation mechanism 130 (blue area in the figure) and the temperature regulation mechanism (not shown in the figure) are used to provide an upward force to the body of the cantilever 110 within the target temperature range. The temperature regulation mechanism can be used to adjust the temperature of the thermal stress compensation mechanism to the target temperature range. In this embodiment, by using the thermal stress compensation mechanism 130 and the temperature regulation mechanism to correct the cantilever deviation, the maximum structural deformation of the cantilever 110 can be controlled within 0.05 mm, thereby meeting the requirements of precision operations (such as the accuracy of ±0.05 mm for active wafer centering in wafer handling and positioning).

[0032] Specifically, in some alternative embodiments, Figure 1 The thermal stress compensation mechanism 130 shown may include a first thermal stress compensation part located on the lower surface of the body of the cantilever portion 110. The first thermal stress compensation part may be adhered (or otherwise fixed) to the lower surface of the body of the cantilever portion 110. The first thermal stress compensation part has a larger coefficient of thermal expansion than the body of the cantilever portion 110, thereby providing an upward force to the lower surface of the body of the cantilever portion 110 within a target temperature range.

[0033] Optionally, in other embodiments, the thermal stress compensation mechanism 130 may also include a second thermal stress compensation portion located on the upper surface of the body of the cantilever portion 110. The second thermal stress compensation portion may be adhered to (or otherwise fixed) on the upper surface of the body of the cantilever portion 110. This second thermal stress compensation portion has a smaller coefficient of thermal expansion than the body of the cantilever portion 110, thereby providing an upward force to the upper surface of the body of the cantilever portion 110 within a target temperature range.

[0034] Preferably, in order to further increase the upward force provided by the thermal stress compensation mechanism 130 to the body of the cantilever portion 110 to overcome the end drooping phenomenon caused by the weight of the cantilever portion 110 itself, a first thermal stress compensation part and a second thermal stress compensation part can be provided on the lower surface and the upper surface of the body of the cantilever portion 110, respectively. The first thermal stress compensation part and the second thermal stress compensation part simultaneously provide upward prestress and constraint force to the cantilever portion 110, thereby counteracting the drooping bending tendency of the cantilever portion 110.

[0035] Continue as Figure 1 As shown, in some embodiments, the target temperature range can be determined by pre-calibration experiments. For example, during the calibration experiment, the present invention can adjust the cantilever 110 to at least one extension state, such as 50%, 80%, or 100% of its total extension length, and measure its longitudinal offset in the corresponding extension state using distance sensors located above and / or below the second end of the cantilever 110. Then, the present invention can adjust the temperature of the temperature regulating mechanism in each extension state to regulate the temperature of the cantilever 110 and the thermal stress compensation mechanism 130 until it is determined that the upward force provided by a thermal stress compensation mechanism 130 is just able to compensate for the sag in each extension state, or to compensate the sag to a target temperature range within a preset range (e.g., 0.05 mm).

[0036] In some embodiments, the body of the cantilever portion 110 may be made of aluminum alloy. For example, the body of the cantilever portion 110 may be made of 6-series aluminum alloy (Al-Mg-Si series) or 7-series aluminum alloy (Al-Zn-Mg-Cu series). The first thermal stress compensation part may be made of nickel-titanium alloy with a coefficient of thermal expansion of -10 × 10⁻⁶.-6 Up to 5×10 -6 / ℃. The phase transition temperature of the first thermal stress compensation part is 60℃~70℃. The target temperature range obtained through calibration experiments is between 60℃~70℃. Based on this, optionally, the first thermal stress compensation part located on the lower surface of the body of the cantilever part 110 can be a thermal stress compensation layer made of nickel-titanium alloy material with a thickness between 0.1~0.2mm. In addition, within the target temperature range of 60℃~70℃, correspondingly, the material of the second thermal stress compensation part located on the upper surface of the body of the cantilever part 110 can be selected from, but is not limited to, Ni-Ti based shape memory alloy (near equiatomic ratio of Ni and Ti), Cu-Al-Ni shape memory alloy (low copper content ratio), and Fe-Mn-Si based shape memory alloy (optimized manganese-silicon ratio).

[0037] Furthermore, the cantilever section 110 for wafer transport often needs to operate in a vacuum and high-temperature environment. Since the first end of the cantilever section 110 is close to the machine body, its temperature is relatively low. However, the second end of the cantilever section 110 is typically exposed to the vacuum and high-temperature environment, resulting in a higher temperature. This creates a temperature gradient between the first and second ends of the cantilever section 110. The high temperature can easily soften the cantilever material at the second end, causing bending deformation and potentially leading to positioning deviations at the second end (i.e., the end point) of the cantilever section 110. For example, in the prior art, the structural deformation at the second end of the cantilever section 110 is typically greater than 0.5 mm per 1000 mm of length.

[0038] In this regard, in the above embodiment, when the cantilever portion 110 with the first thermal stress compensation part is in a high-temperature environment, the lower first thermal stress compensation part, due to the difference in thermal expansion coefficients with the cantilever portion 110, experiences greater free expansion than the upper cantilever portion 110. Due to the structural constraint between the upper and lower layers, the lower first thermal stress compensation part applies an upward prestress in the vertical direction to the upper cantilever portion 110. This prestress can counteract the sagging deformation of the upper cantilever portion 110 caused by its own weight and material softening at high temperatures, thereby maintaining the flatness of the upper cantilever portion 110.

[0039] In other embodiments, when the cantilever portion 110 with the second thermal stress compensation part is in a high-temperature environment, the free thermal expansion of the lower cantilever portion 110 is greater than that of the upper second thermal stress compensation part. Due to the structural constraint between the upper and lower layers, the upper second thermal stress compensation part applies an upward constraint force in the vertical direction to the lower cantilever portion 110. This upward constraint force can counteract the sagging deformation of the lower cantilever portion 110 caused by its own weight and material softening at high temperatures, thereby maintaining the structural flatness of the lower cantilever portion 110 and preventing it from bending or collapsing at high temperatures.

[0040] Furthermore, in some embodiments, the body of the cantilever 110 may be made of a thermally conductive material. The temperature regulation mechanism may include a liquid cooling pipe disposed inside the body of the cantilever 110. Figure 1 (Not shown in the diagram). The coolant circulating within the liquid cooling pipes can be, but is not limited to, water and high-temperature stable silicone oil. High-temperature stable silicone oil has characteristics of low viscosity, high thermal conductivity, and a wide operating stability range (e.g., -50℃ to 300℃). The liquid cooling pipes can cover both the first and second ends of the cantilever portion 110. Furthermore, the liquid cooling pipes can be distributed in a honeycomb pattern within the cantilever portion 110. Through the liquid cooling pipes, the temperature difference between the first and second ends of the cantilever portion 110 can be controlled within a preset first temperature difference range (3~10℃, e.g., 5℃), thereby achieving precise temperature control of the entire cantilever portion 110.

[0041] In the above embodiment, the temperature difference between the first and second ends of the cantilever 110 can be controlled within a first temperature difference range (e.g., 5°C) by means of a liquid cooling pipe, thereby reducing the risk of the cantilever 110 sagging or bending due to uneven temperature at its two ends (forming a temperature gradient). Alternatively, the temperature regulation mechanism can also use components such as air-cooled pipes or semiconductor cooling arrays to achieve a similar temperature regulation effect.

[0042] Furthermore, in some alternative embodiments, the body of the cantilever portion 110 may also be made of a non-thermally conductive material. Alternatively, a person skilled in the art can achieve the same effect of regulating the temperature of the thermal stress compensation mechanism 130 by placing a temperature regulating mechanism on the surface of the thermal stress compensation mechanism 130.

[0043] Continue as Figure 2A As shown, the cantilever 110 may include multiple segmented arms. The first end of the first segment 141 may be connected to the base 120. The first end of the second segment 142 may be connected to the second end of the first segment 141 via a first joint 151. Furthermore, the robotic arm 100 may also include a third segment 143. The first end of the third segment 143 may be connected to the second end of the second segment 142 via a second joint 152, and its second end is connected to the wafer-carrying fingers 160. The third segment 143 may be a U-shaped arm to connect to two fingers 160 via its two second ends respectively, thereby improving wafer transfer efficiency. Figure 2B As shown, the first arm 141 can drive the second arm 142 and the third arm 143 to rotate around the base 120 along the T-axis (i.e., around the Z-axis).

[0044] Specifically, the upper and / or lower surfaces of the first arm 141 may be provided with a first thermal stress compensation mechanism. A first liquid cooling pipe may be provided in the first arm 141. The first liquid cooling pipe may be connected to a constant-temperature liquid source via a first pump. For example, the temperature range of the constant-temperature liquid may be between 24±1℃. The first liquid cooling pipe may cover the first and second ends of the first arm 141 to control the temperature difference between the first and second ends within a preset second temperature difference range (2~5℃, e.g., 3℃), thereby reducing the risk of sagging and bending of the first arm 141 due to uneven temperature at both ends. Further, the first liquid cooling pipe has a first pipe diameter (6~10mm, e.g., ...). 1=8mm). The first liquid cooling tube can cover a first proportion (35%~45%, for example 40%) of the area of ​​the first arm 141.

[0045] Similarly, the upper and / or lower surfaces of the second arm 142 may be provided with a second thermal stress compensation mechanism. A second liquid cooling pipe may also be provided in the second arm 142. The second liquid cooling pipe can be connected to a constant-temperature liquid source via a second pump. For example, the temperature range of the constant-temperature liquid can be between 24±1℃. The second liquid cooling pipe can cover the first and second ends of the second arm 142 to control the temperature difference between its first and second ends within a preset third temperature difference range (2~5℃, e.g., 3℃), thereby reducing the risk of sagging and bending of the second arm 142 due to uneven temperature at its two ends. Further, the second liquid cooling pipe has a second pipe diameter (4~8mm, e.g., ...). 2=6mm). The second liquid cooling tube can cover the second proportion (30%~40%, for example 35%) of the area of ​​the second arm 142.

[0046] In addition, it can be combined Figure 3 A shared understanding. Figure 3 A bottom view schematic diagram of the third arm provided according to some embodiments of the present invention is shown.

[0047] like Figure 1 , Figure 2A and Figure 3 As shown, the upper and / or lower surfaces of the third arm 143 may be provided with a third thermal stress compensation mechanism. A third liquid cooling pipe may be provided in the third arm 143. The third liquid cooling pipe may be connected to a constant-temperature liquid source via a third pump. For example, the temperature range of the constant-temperature liquid may be between 24±1℃. The third liquid cooling pipe may cover the first end and two second ends of the third arm 143 to control the temperature difference between the first end and each of the second ends within a fourth temperature difference range (2~5℃, e.g., 3℃), thereby reducing the risk of sagging and bending of the third arm 143 due to uneven temperature at its two ends. Furthermore, the third liquid cooling pipe has a third pipe diameter (2~6mm, e.g., ...). 3=4mm). The third liquid cooling tube can cover the third proportion (35%~40%, for example 38%) of the area of ​​the third arm 143.

[0048] Optionally, such as Figure 3 As shown, in some preferred embodiments, the third arm 143 may be provided with multiple reinforcing ribs 310 to form a hollow, weight-reducing structure inside the third arm 143. The third liquid cooling pipe may be arranged inside these reinforcing ribs 310. Optionally, multiple reinforcing rib structures may also be provided in the first arm 141 and / or the second arm 142. The first arm 141, in particular, typically bears the greatest stress. Therefore, it can be reinforced by adding multiple reinforcing ribs inside the first arm 141.

[0049] Those skilled in the art will understand that the aforementioned preset second, third, and fourth temperature difference ranges may be the same or different. Furthermore, the aforementioned first, second, and third thermal stress compensation mechanisms may be located at different positions on the first arm 141, second arm 142, and third arm 143, and may be made of different materials, have different thicknesses, and cover different areas.

[0050] In the above embodiment, the temperature regulation mechanism can fully cover the first arm 141 at the root of the cantilever 110, the second arm 142 in the middle, and the third arm 143 at the end, thereby effectively ensuring the temperature uniformity of the entire cantilever (whose length is set between 800-1200mm and its cross-sectional dimensions are 200×50mm) during the operation of the cantilever 110.

[0051] Further, in some preferred embodiments, the first diameter of the first liquid cooling tube within the first arm 141 at the root can be larger than the second diameter of the second liquid cooling tube within the second arm 142 in the middle. Optionally, the second diameter can be larger than the third diameter of the third liquid cooling tube within the third arm 143 at the end. The first arm 141 at the root needs to withstand the maximum force, therefore there is a certain requirement for the thickness of the first arm 141. The internal space of the first arm 141 is relatively large, providing sufficient space for embedding a first liquid cooling tube with a larger diameter (e.g., 8 mm). The second arm 142 in the middle can be thinner than the first arm 141. The third arm 143 is used to connect the fingers that require precise operation, therefore the third arm 143 is typically a thin-diameter, lightweight configuration, with less internal space for embedding the third liquid cooling tube. In this embodiment, the diameters of the liquid cooling tubes at the root, middle, and end within the cantilever portion 110 are gradually reduced to accommodate the internal spaces of arms with different thicknesses.

[0052] Furthermore, in some embodiments, the first and / or third liquid cooling pipes can preferably adopt a ring-shaped distribution structure. The ring-shaped distribution structure is suitable for existing planar clearance structures and some structural components with small footprints. The ring-shaped distribution structure is typically a single-loop circulation with one inlet and one outlet. The circulation rate of the coolant in the same area can be increased by continuously activating the flow function. The second liquid cooling pipe can preferably adopt a serpentine distribution structure. The serpentine distribution structure is generally suitable for planar structures and situations where the resistance of the cooling medium is low. The coverage density of the serpentine distribution structure is better than that of the ring-shaped distribution structure, therefore its cooling effect is better. Coolant circulation can be achieved by intermittently turning on the water pump.

[0053] In some preferred embodiments, the first proportion covered by the first liquid cooling pipe in the first arm 141 at the root can be greater than the third proportion covered by the third liquid cooling pipe in the third arm 143 at the end. Optionally, the third proportion can be greater than the second proportion covered by the second liquid cooling pipe in the second arm 142 in the middle. For example, the first proportion can be 40%, the second proportion can be 35%, and the third proportion can be 38%. In this case, the water channel coverage provided by the liquid cooling pipe in the cantilever 110 can be as high as 38% of the total cantilever volume. Since the water channel at the root is at the position of maximum suspension moment, the water channel density in the first arm 141 is the highest. Compared with the water channel in the middle, the water channel at the end is in the continuously heated part during multi-station handling operations for a long time, so the heat accumulation time in the water channel at the end is the longest. By arranging the water channel density at the end to be greater than that in the middle, the cooling effect on the third arm 143 at the end is improved. In this embodiment, the water channel density at the root, middle and end of the cantilever 110 of the robotic arm is designed differently to accurately meet the cooling requirements of different parts of the cantilever 110.

[0054] Furthermore, in some embodiments of the present invention, a first temperature sensor may be provided on the first arm segment 141. A second temperature sensor may be provided on the second arm segment 142. A third temperature sensor may be provided on the third arm segment 143. The temperature sensors may be attached to the inside of each arm segment to obtain the temperature difference at the front and rear joints of the same arm segment.

[0055] Furthermore, the robotic arm 100 may also include a controller. The present invention can be executed via the controller, in conjunction with the aforementioned temperature sensors. Figure 4 A method for compensating for longitudinal offset of a robotic arm is provided. For example... Figure 4 As shown, the method for compensating for longitudinal offset of the robot arm can mainly include step S410: adjusting the temperature of the thermal stress compensation mechanism of the robot arm to a preset target temperature range via the temperature adjustment mechanism of the robot arm, so as to provide an upward force to the cantilever of the robot arm via the thermal stress compensation mechanism.

[0056] Specifically, in some embodiments, the controller can adjust the first power of the first pump based on the temperature of the first arm segment collected by the first temperature sensor. Similarly, the controller can adjust the second power of the second pump based on the temperature of the second arm segment collected by the second temperature sensor. Furthermore, the controller can adjust the third power of the third pump based on the temperature of the third arm segment collected by the third temperature sensor. In this embodiment, when the robot arm 100 includes only the first arm segment 141 and / or the second arm segment 142 and / or the third arm segment 143, the controller can adjust the power of the first pump and / or the second pump and / or the third pump individually to perform targeted temperature control on each corresponding arm segment.

[0057] Furthermore, in some alternative embodiments, the aforementioned first and / or second and / or third liquid cooling pipes can be connected in series and driven by the same water pump. This series-connected liquid cooling pipe structure allows the controller to synchronously adjust the temperature of each arm segment.

[0058] Furthermore, continue as Figure 2A As shown, in some implementations, the liquid cooling pipe of the aforementioned temperature regulation mechanism and the constant temperature liquid source connected to the base 120 of the robot can form a closed-loop connection. That is, the inlet of the base 120 can be connected to a water injection pipe, and its outlet can be connected to a drain pipe, thus forming a one-in-one-out water circuit design within the cantilever 110 of the robot. Furthermore, the internal liquid cooling pipe can be integrally formed using precision casting, ensuring the stability and efficiency of the robot structure. A first temperature sensor can be embedded in the first liquid cooling pipe on the return water side of the first arm 141. A second temperature sensor can be embedded in the second liquid cooling pipe on the return water side of the second arm 142. A third temperature sensor can be embedded in the third liquid cooling pipe on the return water side of the third arm 143. By placing temperature sensors (e.g., with an accuracy of ±0.1℃) on the return water side of each liquid cooling pipe, temperature data for each area can be collected in real time, ensuring sufficient heat exchange between the coolant and each arm segment, thereby improving the accuracy of temperature acquisition.

[0059] Furthermore, a first flow sensor may be installed on the first liquid cooling pipe. The controller can first collect the first flow rate in the first liquid cooling pipe via the first flow sensor, and calculate the difference between it and the corresponding first target flow rate to determine the first power control amount for the first pump, thereby achieving closed-loop regulation of the first pump's first power. A second flow sensor may be installed on the second liquid cooling pipe. Furthermore, the controller can first collect the second flow rate in the second liquid cooling pipe via the second flow sensor, and calculate the difference between it and the corresponding second target flow rate to determine the second power control amount for the second pump, thereby achieving closed-loop regulation of the second pump's second power. Furthermore, a third flow sensor may be installed on the third liquid cooling pipe. The controller can first collect the third flow rate in the third liquid cooling pipe via the third flow sensor, and calculate the difference between it and the corresponding third target flow rate to determine the third power control amount for the third pump, thereby achieving closed-loop regulation of the third pump's third power.

[0060] Based on this, in some preferred embodiments, the first, second, and third temperature sensors and the first, second, and third flow sensors in the first, second, and third liquid cooling pipes can be combined to further adjust the temperature T1 of the first arm at the root, the temperature T2 of the second arm in the middle, and the temperature T3 of the third arm at the end by adjusting the liquid flow rate in each region of the cantilever 110 according to the correspondence between the temperature difference and the liquid flow compensation value.

[0061] Specifically, the controller can be further configured to increase the third power of the third pump in response to the third arm temperature T3 being greater than the average of the first arm temperature T1 and the second arm temperature T2, i.e., T3 > 0.5(T1 + T2), thereby reducing the high temperature at the end of the cantilever 110. For example, the controller can control the liquid flow rate output by the third pump to be increased by 10% to 30% (e.g., 20%). Since the end of the cantilever 110 is a critical area for positioning and requires extremely high accuracy, cooling of the end of the cantilever 110 can be prioritized to reduce the risk of end-positioning misalignment.

[0062] Furthermore, in some alternative embodiments, the controller may increase the second power of the second pump in response to the second arm temperature T2 being greater than a preset multiple of the first arm temperature T1, thereby reducing the high temperature in the middle of the cantilever 110. For example, the preset multiple may be between 1 and 1.5. When T2 > 1.2 T1, the controller may control the liquid flow rate output by the second pump to be increased by 5% to 20% (e.g., 10%). Since the middle of the cantilever 110 is a sensitive area for deformation and requires fine control, after the priority cooling of the end of the cantilever 110 is completed, the middle of the cantilever 110 can be cooled subsequently to reduce the risk of high-temperature deformation in the middle.

[0063] Furthermore, in some embodiments, the present invention may also determine the longitudinal offset of the cantilever 110 relative to its target height via at least one sensor, and adjust the temperature of the thermal stress compensation mechanism 130 to the target temperature range corresponding to the longitudinal offset via the aforementioned temperature adjustment mechanism, so as to compensate the longitudinal offset of the cantilever 110 as a whole, or to compensate the longitudinal offset of each segment of the cantilever 110 separately.

[0064] For example, the aforementioned sensor may be a distance sensor located above and / or below the second end (end) of the cantilever portion 110. The present invention can detect the actual distance from the distance sensor to the second end of the cantilever portion 110 via this distance sensor, and characterize the longitudinal offset of the second end of the cantilever portion 110 relative to its target height by calculating the difference between the actual distance and a preset target distance. Subsequently, the present invention can incorporate this longitudinal offset into a pre-calibrated longitudinal offset-temperature correspondence to determine the target temperature range required to compensate for the longitudinal offset, and adjust the temperature of the thermal stress compensation mechanism 130 to this target temperature range via a temperature adjustment mechanism to compensate for the longitudinal offset.

[0065] For example, the aforementioned sensor can be a position sensor located at the second end (end) of the cantilever 110. The present invention can detect the lateral elongation of the second end of the cantilever 110 via this position sensor and substitute this lateral elongation into a pre-calibrated lateral elongation-longitudinal offset mapping model to determine the longitudinal offset of the second end of the cantilever 110 relative to its target height. In some embodiments, the present invention can use the position of the second end of the cantilever 110 when the cantilever 110 is in a fully retracted state as the initial position, and the aforementioned lateral elongation is the straight-line distance from the current position of the second end detected by the position sensor to the initial position. Then, the present invention can, as described above, substitute this longitudinal offset into a pre-calibrated longitudinal offset-temperature correspondence to determine the target temperature range required to compensate for the longitudinal offset, and adjust the temperature of the thermal stress compensation mechanism 130 to the target temperature range via a temperature adjustment mechanism to compensate for the longitudinal offset.

[0066] For example, the aforementioned position sensor can also be implemented by an angle sensor on the lateral telescopic shaft of the base 120. Specifically, the present invention can perform trigonometric function calculations based on the angle signal collected by the angle sensor and the length of the cantilever 110 to determine the lateral elongation of the second end (end) of the cantilever 110. Then, as described above, the lateral elongation is substituted into a pre-calibrated lateral elongation-longitudinal offset mapping model to determine the longitudinal offset of the second end of the cantilever 110 relative to its target height. And, as described above, the longitudinal offset is substituted into a pre-calibrated longitudinal offset-temperature correspondence to determine the target temperature range required to compensate for the longitudinal offset. Then, the temperature of the thermal stress compensation mechanism 130 is adjusted to the target temperature range via a temperature adjustment mechanism to compensate for the longitudinal offset.

[0067] Continue as Figure 1 As shown, in some other embodiments of the present invention, the base 120 may be provided with at least a lifting shaft. The first end of the cantilever 110 is connected to the lifting shaft. The lifting shaft can be driven to rise and fall via a root direct-drive servo motor 121. The displacement of the cantilever 110 can be adjusted longitudinally via the rising and falling movement of the lifting shaft.

[0068] Specifically, please refer to Figure 5 . Figure 5 A flowchart is shown of a method for compensating for longitudinal offset of a robotic arm according to other embodiments of the present invention.

[0069] like Figure 5 As shown, in some embodiments, the controller can be configured to perform the following steps S510-S520. Step S510 is to determine the longitudinal offset of the second end of the cantilever 110 relative to its target height. Step S520 is to control the lifting shaft to adjust the height of the first end of the cantilever 110 according to the longitudinal offset, thereby completing the longitudinal offset compensation of the Z-axis.

[0070] Furthermore, it can be combined with Figure 1It is understood that a distance sensor can be provided above and / or below the wafer carrier position for picking up and placing wafers at the second end of the cantilever 110. The distance sensor can obtain the value of the sag of the second end of the cantilever 110 in the Z-axis direction. The type of distance sensor may include, but is not limited to, a laser displacement sensor (resolution 0.005mm). The controller can be connected to the distance sensor to receive the distance information of the sag fed back by the distance sensor. During the execution of the above step S510, the actual distance from the distance sensor to the second end of the cantilever 110 can be obtained via the distance sensor. Then, based on the difference between the actual distance and the standard distance from the distance sensor to the target height, the longitudinal offset of the second end of the cantilever 110 relative to its target height is determined. Then, based on the longitudinal offset, the lifting shaft can be controlled to adjust the height of the first end of the cantilever 110, and / or the temperature adjustment mechanism can be controlled to adjust the temperature of the thermal stress compensation mechanism, thereby completing the longitudinal offset compensation of the cantilever 110. Thus, in this embodiment, real-time longitudinal offset compensation of the cantilever 110 is realized based on the distance sensor.

[0071] In some alternative embodiments, the controller is also connected to the aforementioned position sensors and configured with a pre-calibrated lateral elongation-longitudinal offset mapping model. This lateral elongation-longitudinal offset mapping model indicates the longitudinal offset generated at the end of the cantilever 110 at different elongation positions. The position sensor can be located at the second end (end) of the cantilever 110. The present invention can detect the lateral elongation of the second end of the cantilever 110 via the position sensor and substitute this lateral elongation into the pre-calibrated lateral elongation-longitudinal offset mapping model to determine the longitudinal offset of the second end of the cantilever 110 relative to its target height. Then, based on the longitudinal offset, the lifting shaft can be controlled to adjust the height of the first end of the cantilever 110, and / or the temperature adjustment mechanism can be controlled to adjust the temperature of the thermal stress compensation mechanism, thereby completing the longitudinal offset compensation of the cantilever 110. Thus, in this embodiment, real-time longitudinal offset compensation of the cantilever 110 is achieved based on the position sensor.

[0072] In some alternative embodiments, the base 120 may also be provided with a lateral telescopic shaft (i.e., the R-axis), which is equipped with an angle sensor. The first end of the cantilever 110 can be connected to the lateral telescopic shaft. The present invention can perform trigonometric function calculations based on the angle signal collected by the angle sensor and the length of the cantilever 110 to determine the lateral extension of the second end (end) of the cantilever 110. A pre-calibrated lateral extension-longitudinal offset mapping model can be configured in the controller. For example, when the lateral telescopic shaft extends by 5 mm, a single 2 mm compensation stroke for longitudinal offset of the Z-axis can be performed. During the execution of the above step S510, the lateral extension of the second end of the cantilever 110 can be obtained via the lateral telescopic shaft. Then, this lateral extension is substituted into the lateral extension-longitudinal offset mapping model to determine the longitudinal offset of the second end of the cantilever 110 relative to its target height. Then, based on the longitudinal offset, the height of the first end of the cantilever 110 can be adjusted by controlling the lifting shaft, and / or the temperature of the thermal stress compensation mechanism can be adjusted by controlling the temperature regulating mechanism, thereby completing the longitudinal offset compensation of the cantilever 110. Thus, in this embodiment, based on the lateral telescopic shaft, real-time longitudinal offset compensation of the cantilever 110 is achieved during the lateral extension process.

[0073] In some alternative embodiments, the controller is also connected to the aforementioned temperature sensors. Furthermore, the controller may be configured with a pre-calibrated temperature-longitudinal offset mapping model. This model indicates the longitudinal offset of the cantilever 110 caused by deformation due to temperature changes. For example, for every 1°C increase in temperature, the corresponding end sag changes by 0.03 mm. During step S510, the actual temperature of the cantilever 110 can be obtained via the temperature sensors. This actual temperature is then substituted into the temperature-longitudinal offset mapping model to determine the longitudinal offset of the second end of the cantilever 110 relative to its target height. Then, based on this longitudinal offset, the lifting shaft can be controlled to adjust the height of the first end of the cantilever 110, and / or the temperature adjustment mechanism can be controlled to adjust the temperature of the thermal stress compensation mechanism, thereby completing the longitudinal offset compensation of the cantilever 110. Thus, in this embodiment, based on the temperature sensors, real-time longitudinal offset compensation of the cantilever 110 is achieved during changes in ambient temperature.

[0074] Furthermore, in some preferred embodiments, the aforementioned distance sensor, temperature sensor, and lateral telescopic shaft can be combined to perform multi-level longitudinal offset compensation on the height of the first end of the cantilever 110, including point-based, process-based compensation during temperature changes, and process-based compensation during lateral extension, thereby achieving multi-level accurate compensation for the Z-axis longitudinal offset. The aforementioned algorithm is constructed and controlled by a controller via a closed-loop monitoring system to perform real-time algorithm compensation calculation. Then, via the lifting shaft and motor located in the base 120, the vertical coordinate position of the second end of the cantilever 110 on the Z-axis is compensated in real time, thereby overcoming the deficiency of existing Active Wafer Centering (AWC) algorithms in achieving Z-axis coordinate compensation.

[0075] Furthermore, in other embodiments, the target height can be determined based on the wafer carrier height at the second end of the cantilever 110, the load lock height, and the corresponding lower limit of the safety clearance. Specifically, during the testing phase, the theoretical positions of the first arm 141 at the root, the second arm 142 in the middle, and the third arm 143 at the end of the cantilever 110 can be determined through teaching. Then, the lower limit of the safety clearance between each arm and the aforementioned contact components is calculated. For example, the first safety clearance between each arm and the wafer carrier height is at least 2.5 mm. The second safety clearance between each arm and the load lock outlet height is at least 1.5 mm. By taking into account the lower limit of the safety clearance between the robot arm 100 and each contact component during the transmission process during the calibration of the target height, it can be ensured that no collision occurs during the movement of each arm.

[0076] Those skilled in the art will understand that although the present invention describes an embodiment for adjusting the longitudinal offset of the cantilever 110 using a thermal stress compensation mechanism and a temperature regulation mechanism, and also describes an embodiment for compensating the longitudinal offset of the cantilever 110 by a lifting shaft, these are only two non-limiting embodiments.

[0077] Alternatively, in other embodiments, based on the concept of the present invention, those skilled in the art can easily conceive of an implementation method that combines a thermal stress compensation mechanism, a temperature adjustment mechanism, and a lifting shaft to jointly compensate for the longitudinal offset of the cantilever 110, in order to achieve a more accurate compensation effect.

[0078] In summary, this invention provides a robotic arm, a method for compensating for longitudinal offset of the robotic arm, and a computer-readable storage medium, which can improve the sagging phenomenon of the cantilever end of the robotic arm caused by its own gravity, thereby improving the motion accuracy of the robotic arm during long-distance transmission, ensuring the stability of workpiece transmission over long periods, and helping to expand the application boundaries of the robotic arm in high-precision manufacturing scenarios.

[0079] Although the methods described above are illustrated and depicted as a series of actions for the sake of simplicity, it should be understood and appreciated that these methods are not limited by the order of the actions, as some actions may occur in a different order and / or concurrently with other actions from the illustrations and descriptions herein or not illustrated and described herein but which may be understood by those skilled in the art, according to one or more embodiments.

[0080] Those skilled in the art will understand that information, signals, and data can be represented using any of a variety of different techniques and skills. For example, the data, instructions, commands, information, signals, bits, symbols, and chips described throughout the above description can be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, light fields or optical particles, or any combination thereof.

[0081] Those skilled in the art will further appreciate that the various illustrative logic blocks, modules, circuits, and algorithm steps described in conjunction with the embodiments disclosed herein can be implemented as electronic hardware, computer software, or a combination of both. To clearly illustrate this interchangeability between hardware and software, the various illustrative components, blocks, modules, circuits, and steps are described above in a generalized manner in terms of their functionality. Whether such functionality is implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system. Those skilled in the art may implement the described functionality in different ways for each specific application, but such implementation decisions should not be construed as departing from the scope of the invention.

[0082] Although the controller described in the above embodiments can be implemented through a combination of software and hardware, it is understood that the controller can also be implemented in software or hardware. For hardware implementation, the controller can be implemented using one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, other electronic devices for performing the above functions, or a selection of combinations of the above devices. For software implementation, the controller can be implemented using independent software modules such as procedures and functions running on a general-purpose chip, each module performing one or more functions and operations described herein.

[0083] The various illustrative logic modules and circuits described in conjunction with the embodiments disclosed herein may be implemented or performed using a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. The general-purpose processor may be a microprocessor, but in alternatives, it may be any conventional processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors cooperating with a DSP core, or any other such configuration.

[0084] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of both. The software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to a processor such that the processor can read and write information to / from the storage medium. In an alternative, the storage medium may be integrated into the processor. The processor and storage medium may reside in an ASIC. The ASIC may reside in a user terminal. In an alternative, the processor and storage medium may reside as discrete components in the user terminal.

[0085] In one or more exemplary embodiments, the described functionality may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software as a computer program product, the functionality may be stored or transmitted as one or more instructions or code on or via a computer-readable medium. A computer-readable medium includes both computer storage media and communication media, encompassing any medium that facilitates the transfer of a computer program from one location to another. A storage medium may be any available medium accessible to a computer. By way of example and not limitation, such a computer-readable medium may include RAM, ROM, EEPROM, CD-ROM or other optical disc storage, disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and is accessible to a computer. Any connection is also legitimately referred to as a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of a medium. As used in this article, disk and disc include compact discs (CDs), laser discs, optical discs, digital multi-purpose discs (DVDs), floppy disks, and Blu-ray discs. Disks typically reproduce data magnetically, while discs reproduce data optically using lasers. Combinations of these should also be included within the scope of computer-readable media.

[0086] The prior description of this disclosure is provided to enable any person skilled in the art to make or use this disclosure. Various modifications to this disclosure will be apparent to those skilled in the art, and the general principles defined herein may be applied to other variations without departing from the spirit or scope of this disclosure. Therefore, this disclosure is not intended to be limited to the examples and designs described herein, but should be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A robot, characterized in that include: The cantilever section has a first end connected to a base and a second end suspended in the air. The body of the cantilever section is made of thermally conductive material and is equipped with a thermal stress compensation mechanism and a temperature regulation mechanism. The thermal stress compensation mechanism has a different coefficient of thermal expansion than the body of the cantilever section and is used to provide an upward force to the body of the cantilever section within a target temperature range. The temperature regulation mechanism includes a liquid cooling pipe located inside the body of the cantilever section and is used to regulate the temperature of the thermal stress compensation mechanism to the target temperature range. The cantilever section includes multiple segments and a wafer-carrying finger. The first end of the first segment is connected to the base. The first end of the second segment is connected to the second end of the first segment via a first joint. The first end of the third segment is connected to the second end of the second segment via a second joint. The second end of the third segment is connected to the finger. The second segment is equipped with a second liquid cooling pipe and a second temperature sensor. The second liquid cooling pipe is connected to a constant temperature liquid source via a second pump. The third segment is equipped with a third liquid cooling pipe, a third temperature sensor, and a third thermal stress compensation mechanism. The third liquid cooling pipe is connected to the constant temperature liquid source via a third pump. as well as The controller is configured to: adjust the second power of the second pump based on the temperature of the second arm acquired by the second temperature sensor; and adjust the third power of the third pump based on the temperature of the third arm acquired by the third temperature sensor.

2. The robot of claim 1, wherein The thermal stress compensation mechanism includes a first thermal stress compensation part located on the lower surface of the cantilever body, which has a larger coefficient of thermal expansion than the cantilever body, to provide an upward force to the lower surface of the cantilever body within the target temperature range, and / or The thermal stress compensation mechanism includes a second thermal stress compensation part located on the upper surface of the body of the cantilever portion, which has a smaller coefficient of thermal expansion than the body of the cantilever portion, so as to provide an upward force to the upper surface of the body of the cantilever portion within the target temperature range.

3. The robotic arm as described in claim 2, characterized in that, The main body of the cantilever is made of aluminum alloy, the first thermal stress compensation part is made of nickel-titanium alloy, and the target temperature range is between 60℃ and 70℃.

4. The robotic arm as described in claim 1, characterized in that, The liquid cooling pipe covers the first and second ends of the cantilever to control the temperature difference between the first and second ends within a preset first temperature difference range.

5. The robotic arm as described in claim 4, characterized in that, The first arm section is equipped with a first liquid cooling pipe, which covers the first end and the second end of the first arm section to control the temperature difference between the first end and the second end within a preset second temperature difference range. The second liquid cooling tube covers the first and second ends of the second arm section to control the temperature difference between the first and second ends within a preset third temperature difference range.

6. The robotic arm as described in claim 5, characterized in that, The third liquid cooling pipe covers the first and second ends of the third arm section to control the temperature difference between the first and second ends within a preset fourth temperature difference range.

7. The robotic arm as described in claim 6, characterized in that, The robotic arm includes two fingers, and the third arm is a U-shaped arm that connects the two fingers via its two second ends. The third liquid cooling pipe covers the first end and the two second ends of the third arm to control the temperature difference between the first end and each of the second ends within the fourth temperature difference range.

8. The robotic arm as described in claim 6, characterized in that, The first liquid cooling tube has a first diameter and covers a first proportion of the area of ​​the first arm section, and / or The second liquid cooling tube has a second diameter and covers a second proportion of the area of ​​the second section arm, and / or The third liquid cooling pipe has a third diameter and covers a third proportion of the area of ​​the third arm section.

9. The robotic arm as described in claim 8, characterized in that, The first pipe diameter is larger than the second pipe diameter, and / or the second pipe diameter is larger than the third pipe diameter, and / or The first ratio is greater than the third ratio, and / or the third ratio is greater than the second ratio.

10. The robotic arm as described in claim 6, characterized in that, The first liquid cooling pipe and / or the third liquid cooling pipe adopt a ring distribution structure, and / or the second liquid cooling pipe adopts a serpentine distribution structure.

11. The robotic arm as described in claim 6, characterized in that, The first arm is equipped with a first temperature sensor, the first liquid cooling pipe is connected to a constant temperature liquid source via a first pump, and the controller is further configured to: The first power of the first pump is adjusted based on the temperature of the first arm section collected by the first temperature sensor.

12. The robotic arm as described in claim 11, characterized in that, The first temperature sensor is embedded in the first liquid cooling pipe on the return water side of the first arm section, and / or The second temperature sensor is embedded in the second liquid cooling pipe on the return water side of the second arm, and / or The third temperature sensor is embedded in the third liquid cooling pipe on the return water side of the third arm.

13. The robotic arm as described in claim 11, characterized in that, The first liquid cooling pipe is also equipped with a first flow sensor, and the controller further adjusts the first power of the first pump in a closed loop based on the first flow rate collected by the first flow sensor, and / or The second liquid cooling pipe is also equipped with a second flow sensor, and the controller further adjusts the second power of the second pump in a closed loop based on the second flow rate collected by the second flow sensor, and / or The third liquid cooling pipe is also equipped with a third flow sensor, and the controller further adjusts the third power of the third pump in a closed loop based on the third flow rate collected by the third flow sensor.

14. The robotic arm as described in claim 11, characterized in that, The controller is further configured to: In response to the third arm temperature being greater than the average of the first arm temperature and the second arm temperature, the third power of the third pump is increased; and / or In response to the second arm temperature being greater than a preset multiple of the first arm temperature, the second power of the second pump is increased.

15. The robotic arm as described in claim 6, characterized in that, The thermal stress compensation mechanism further includes a first thermal stress compensation mechanism disposed on the first arm section and / or a second thermal stress compensation mechanism disposed on the second arm section.

16. The robotic arm as described in claim 1, characterized in that, Also includes: A sensor is used to determine the longitudinal offset of the cantilever relative to its target height, wherein the temperature adjustment mechanism adjusts the temperature of the thermal stress compensation mechanism to the target temperature range corresponding to the longitudinal offset in order to compensate for the longitudinal offset.

17. The robotic arm as described in claim 16, characterized in that, The sensor includes a distance sensor and / or a position sensor, wherein, The distance sensor is positioned above and / or below the second end of the cantilever, and is used to detect the actual distance from the distance sensor to the second end of the cantilever. The difference between the actual distance and a preset target distance is used to characterize the longitudinal offset of the second end of the cantilever relative to its target height. The position sensor is used to determine the lateral elongation of the second end of the cantilever and to characterize the longitudinal offset of the second end of the cantilever relative to its target height by means of the lateral elongation.

18. The robotic arm as described in claim 1, 16, or 17, characterized in that, The base is provided with at least a lifting shaft, the first end of the cantilever is connected to the lifting shaft, and the robotic arm also includes a controller configured to: Determine the longitudinal offset of the second end of the cantilever relative to its target height; and Based on the longitudinal offset, the lifting shaft is controlled to adjust the height of the first end of the cantilever.

19. The robotic arm as described in claim 18, characterized in that, The controller is also connected to a distance sensor, which is located above and / or below the wafer carrier position for picking up and placing wafers at the second end of the cantilever. The step of determining the longitudinal offset of the second end of the cantilever relative to its target height includes: The actual distance from the distance sensor to the second end of the cantilever is obtained via the distance sensor; and the longitudinal offset of the second end of the cantilever relative to its target height is determined based on the difference between the actual distance and the standard distance from the distance sensor to the target height.

20. The robotic arm as described in claim 18, characterized in that, The controller is also connected to a temperature sensor and configured with a pre-calibrated temperature-longitudinal offset mapping model. The step of determining the longitudinal offset of the second end of the cantilever relative to its target height includes: The actual temperature of the cantilever is obtained via the temperature sensor; and The actual temperature is substituted into the temperature-longitudinal offset mapping model to determine the longitudinal offset of the second end of the cantilever relative to its target height.

21. The robotic arm as described in claim 18, characterized in that, The controller is also connected to a position sensor and configured with a pre-calibrated lateral elongation-longitudinal offset mapping model. The step of determining the longitudinal offset of the second end of the cantilever relative to its target height includes: The lateral elongation of the second end of the cantilever is obtained via the position sensor; and Substitute the lateral elongation into the lateral elongation-longitudinal offset mapping model to determine the longitudinal offset of the second end of the cantilever relative to its target height.

22. The robotic arm as described in claim 18, characterized in that, The base is also provided with a lateral telescopic shaft, and the first end of the cantilever is also connected to the lateral telescopic shaft. The controller is also connected to an angle sensor located on the lateral telescopic shaft and is configured with a pre-calibrated lateral elongation-longitudinal offset mapping model. The step of determining the longitudinal offset of the second end of the cantilever relative to its target height includes: The angle signal of the lateral telescopic axis is obtained via the angle sensor; Based on the angle signal and the length of the cantilever, determine the lateral elongation of the second end of the cantilever; and Substitute the lateral elongation into the lateral elongation-longitudinal offset mapping model to determine the longitudinal offset of the second end of the cantilever relative to its target height.

23. The robotic arm as described in claim 18, characterized in that, The target height is determined based on the wafer carrier height at the second end of the cantilever, the load latch cavity height, and the corresponding lower limit of the safety clearance.

24. A method for compensating for longitudinal offset of a robotic arm, characterized in that, include: The temperature of the thermal stress compensation mechanism of the robot hand is adjusted to a preset target temperature range by means of the temperature adjustment mechanism of the robot hand as described in any one of claims 1 to 23, so as to provide an upward force to the cantilever portion of the robot hand via the thermal stress compensation mechanism.

25. A computer-readable storage medium storing computer instructions thereon, characterized in that, When the computer instructions are executed by the processor, the longitudinal offset compensation method of the robot arm as described in claim 24 is implemented.

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